drc's post about the reworked advogato stuff convinced me to finally learn enough about CSS to make bordered boxes. You can do it, but finding out how isn't easy. The best way appears to be creating an element with table-cell display attributes, like this:

span.cert {
    display: table-cell;
    background-color: inherit;
    padding: 0;
    margin: 0;
    border: 2px;
}

Of course, Gecko is the only rendering engine that gets this right (although Opera does pretty well). Konqueror draws it correctly but then fills background over the text. IE does some weird word-wrapping. Looks good in w3-mode though.

So you can get advogato-like output using CSS, but it's not well-supported yet.

If you'd like to see the resultant output, check out thunk.